The blaze started in the first floor of a flat in Butts Meadow on Thursday afternoon, August 10.
Firefighters attended just before 3pm and extinguished the flames.
Police said remains of a cannabis crop were found inside the property.
Two people were arrested in connection with the incident.
Officers said Roxy-Lee Jackson, 32, unemployed, of New Road, Billingshurst, appeared at Brighton Magistrates’ Court on August 12, charged with arson and possession with intent to supply cannabis. The case was sent for trail at Lewes Crown Court on September 8.
A 35-year-old man, from Billingshurst, was arrested on suspicion of arson and production of cannabis and has been released under investigation.